Air brake for aircraft



AIR BRAKE FOR AIRCRAFT Filed, May 11, 1942 5 Sheets-Sheet* l Jam 8, 1946 R. T. YOUNGMAN 2,392,443

'AIR BRAKE FOR AIRCRAFT Filed May 11, 1942 s sneek-sheet 2 ATTORNEY Jan. 8, 1946.- R, T YQUNGMAN 392,443

AIR BRAKE FOR AIRCRAFT Filed May 11, 1942 s Sheets-sheet 5 irl-:.1211

a INVENTDR Raaf/rr 7711.507' )bw/64mm T'' ATTORVNEY Patented Jan. 8, 1946 muren f N-ParaNr orales AIRBRAKE Foa;entonar'ri Robert Talbot Yungman, Aldrslohizland.

Application Mayjlfl, 1942;SerialNmvMzAG In Great Britain Angustia, 21941v s claims. (011244-413) This invention relatesto an air-brake `for aircraftof the kind comprising a yflap orthe'like which can be projected into theair-'stream by the extension of abellofws device into which'air is driven by the forward movement of the'aircraft. In a known device of this kind means arepro-` vided for enabling the :bellows device to be placedintocommunication with, `or vbe cut off vfrom communication with, regions of high' and also low pressure outsidethe aircraft, for example, a high pressure region under thewing and a low pressure region above the wing, andv thesemeans nave been interconnected so that "when the one is open the other is closed and vice Aversa.

In such anarrangement the pressure or suction developed inside the bellowsdevicedepends to a large extent uponthe-incidence of the wing to the relative wind, and, in consequence, the pressure or suction -may vary considerably `and detract from effective operation. In particular, if the aircraft be inverted vthe pressiue opening mayv become a suction opening, or pressure may be developed at the suction opening, and this, combined with the outward negative pressure lon the flap itself, may inadvertently cause the flapj to open,V 4which would Vpossibly result in the aircraft going out of control.

The object of the present invention is to provide a pneumatically operated flap or like movable surface, the opening or closing of which is controlled positively by improved means under all attitudes of fiight by dynamic pressure or suction derived from the relative wind. 1

To this end and in accordance with the invention, the bellows device is connected with a Venturi tube situated in a fore and aft direction in the air stream and connected with said bellows device by a pipe leading thereto from the throat of the Venturi tube, said tube being provided in the rear of said throat with a butterfly shutter or like closing means whereby the opening presented by the Venturi tube may lbe converted, at the will of the pilot, to a pressure opening, when the shutter is closed, or to a suction opening, when the shutter is open. x

The device and the method of operation may be used for the purposes of a lift flap, air brake, trimmer, for any other purpose Where it is necessary to move a surface in opposition to the resistance of the relative wind.

By these means it can be made certain that even when the aircraft is in inverted flight, the suction generated in the Venturi tube or the like willl always be greater than the negative pressure generated on the outside of the flap when lll the aircraft isl inthe inverted lattitl'ide,andy -rthe iiap 1 will 1 accordingly 'remain closed* whenf `the shutter is fopen.. By y partially closing'the shutter it lis also :possible to control -tl'ie angular v`'movementlofv the .-apwithin predetermined limits.

In such an application of thek invention, the

air brake may be'operated in'con'iunction with a similar form vof il-apici trimmeron the'tail plane surface for the `purpose of` -c'zounteractingY 'the change of trim vwhen-the brake flaps lare-lowered. This 2trimmer 'flap `can e be connected with f the same Venturi tubefor it'maybe-controlledinde- 'The 4invention is illustrated by way fof.. example in the*A accompanying diagrammatic drawings of which Figure'l shows-in fore-'and aft-section aV bellows` device with ai Venturi tube'v pressure opening, -thefbellowsfdevice being'rin the collapsed condition; Figure 2 is a similar View showing the bellows device in its extended condition; Figure 32 is a front'view--andfligure 4 'is a plan of an'aircraftlflttedwith air brakes'arranged'in accordance Iwith the invention; Figure =5 is `a' side view 'of a modied vconstructionyFigure. 6''is a plan @view vof 'thesaine; Figure '7` is -a .planzview of 'ia further embodiment;'Figure T8 isfa front view of the form shown in Figure 7; Figure 9 isan enlarged plan detail of the tail portion of the arrangement shown in Figures 7 and 8; and, Figure l0 shows in fore and aft section the bellows arrangement employed in the embodiment of Figures 7 to 9, inclusive.

As shown the bellows device is constituted by three reinforced plates a, b and c covered with fabric and hingedly united as at d, e, whilst the plate a is hinged as at f at the front end of a recess g in an aircraft wing h, it being understood that laterally the bellows device has co1- lapsible side members j, 7c and that suitable sealing strips are provided at the joints. m is a curtain or strip of fabric one end of which is secured at the point f, and the other end of which is connected with the junction of the plates b and c at e to limit the extent to which the bellows device can open.

A duct n leads from the interior of the bellows device to the throat of a Venturi tube o situated beneath the fuselage p of the aricraft and having a buttery shutter q at the rear end of its throat, operable by means of a crank r on its spindle s and a link t leading to the pilot's cockpit.

In use, the Venturi tube o and duct n constitute a pressure opening to the bellows device when said tube is situated in a region of high pressure and the valve q is closed, as indicated It is to !be understood that a diaphragm valve situated in a fore and aft direction in the airstream, a tube connecting the bellows device withV thethroat of the Venturi tube, and closing means operable from the pilots cockpit provided in said Venturi tube inrear of said throat, said Venturi tube constituting a pressure opening when said closing means is adjusted to one position and constituting a suction opening when said closing means is adjusted to a second position, whereby vthe member'operable by said .bellows device may Y beprojected or retracted even though inversion yof the aircraft may result in inversion of the presor other suitable device Vmay be substituted for the buttery valve q and Ythat if desired the valve maybe controlled by anyl convenient electrical, hydraulic or mechanical means.

sure in the region in which said Venturi tubeV is situated.

-In the drawings the Venturitube, o is shown may be fitted in any other suitable position the air stream.

f Ix1 1igi1 res 5V to.lOLinclusix/e,.are shown two modiiied Vforms, of the-inventionrin which the. air

brake is operated VinjccmjunctiOnv With a similar Y formr of YiiapY or trimmer on the tail plane surface for thepurpose of counter-acting the change of trim when the brake lflaps are lowered.

In the formwshown, in Figures 5 and 6 the tail fitted at the underside of the hiselage pibut it 2. An airbrake for an aircraft as claimed in "l claim 1 ink conjunction with a similar device at the surface of the tail plane of the aircraft, both i said airbrake and said similar device being ccn-r nected with the Venturi tube.

3. An air brake for an airplane having wings and a tail plane, said air brake comprising a bellows` device into -which airva'may be drivenpbyi the forward movement of theairplane, a member carried by the wings and operable .by said bellows device, said member being projected into'the air stream when air is driven into said bellows Y device, a Venturi tube situated in a fore and aft plane u isprovided with trimmer aps af similar Y in form anvdroperation tothe flaps a4 of Figures 1Yto4, inclusive. bellowssuppliedhwith airthrough the ductva' which is connected with the venturio';

In the form shown in Figures 7 to 10,-inc1usiveL the tailplane is also provided with iiaps a. actuated by bellows which are supplied by air through the extension Vduct 111 leading from the duct n connected withfthe venturi o. The operation of both theseforms will be obvious from theY above description. Inclaim: e y l. An Vairbrake Yfor an aircraft ycomprising va bellows device into `which air maybe driven by thev forward movement ofthe aircraft, a member operable 'by said bellows device, Vsaid member being projected into the airstream when, air is driven into said bellows device,v a Venturi .tube

Y'I'hereflaps a' :are Y'operatedby direction in the air stream; a. tube connecting the bellows device with the throat of the'Venturi tube, lclosinrg ymeans operable from lthe pilots cockpit provided insaid Venturi tube in the rear of said throat, said Venturi tube constituting'a pressure opening when said closing means is adjusted to one position and constituting a suction opening when said closing means isA adjusted to a second position, whereby the mem-A beroperable by said bellows device may be projected or restricted even vthough inversion of the airplane may result in inversion ofthe pressure in the region in which said Venturi tube is situated, a similar member carried |by the Ytail plane, and a similar bellows Venturi tube, connecting tube, and closing means for operatingv and con- Y trolling said similar member. Y

vRorliR'r TALBOT YOUNGMANQ 

